Everybody who cares passionately about the Union should speak up in its defence. As we approach the date for the referendum on Scotland’s independence, details are starting to emerge of the substantial economic impact independence might have on people’s lives.

Supermarkets have warned that Alex Salmond’s anti-business policies are already discouraging them from building more stores north of the border. His controversial supermarket tax costs retailers more that £30 million a year, and one industry source says that this wipes out 30 per cent of the operating profits for a standard supermarket.

But if Scotland goes it alone, things could get even worse. Last week, three of the UK’s biggest supermarkets warned that consumers in an independent nation will face the possibility of higher food bills because their supply chains and pricing policies are designed according to the premise of a United Kingdom. The higher costs of distribution in Scotland are currently absorbed by the UK market, and that arrangement would presumably end after independence.

Many other businesses are probably thinking along the same lines, weighing up the benefits and risks of investing in what will suddenly become a foreign country. Meanwhile, savers south of the border will eventually be forced to ask themselves whether they want to keep their savings in what could become foreign-owned banks in an independent Scotland which is currently uncertain even about what currency it will use.

Concerned business people have to let voters know the truth. Yet Iain Martin, writing in today’s Sunday Telegraph, reveals that some are nervous about doing so. The populist and rhetorically abrasive Scottish Nationalist Party is exerting political pressure to try to gag them. Our report quotes one chief executive as saying: “Most business leaders are keeping their heads down on this issue, mainly due to the aggressive reaction any expressed negative opinion provokes from Alex Salmond and his cohorts.” Indeed, when the supermarkets voiced their concerns about a potential rise in the cost of distribution, pro-independence activists accused them of being anti-patriotic, and even proposed a boycott.

While some remain silent out of fear, others may do so out of complacency, reasoning that because polls currently show that the nationalists are going to lose, they should sit the debate out and be comfortably above the fray. Yet Mr Salmond is a masterful campaigner and there is a risk that if the Union campaign fails to energise voters, then Scotland might end up sleepwalking into independence. In other words, business leaders privately concerned about the effects of nationalism would be well advised to express those fears in public.

Of course, it is not just the economic case for the Union that we need to hear more of. What started as an act of convenience in 1707 has created one of the most dynamic national relationships in history. It fostered the Enlightenment and industrialisation, built an empire and a commonwealth, and stood shoulder-to-shoulder against fascism in the Thirties and Forties. The United Kingdom is bonded together partly by necessity, but also by a fraternal affinity that we should all be more confident about defending. The Union is worth fighting for.